Dynamo-electric machinery.



No. 811,812. PATENTED JAN. 30, 1906, J. H. ST. E. MAWDSLEY. DYNAMO ELECTRIC MACHINERY.

APPLICATION FILED NOV. 30. 1903.

2 SHEETSSHEET 1.

No. 811,312- PATENTED JAN. 30, 1906. J. H. ST. E. MAWDSLEY. DYNAMO ELECTRIC MACHINERY.

APPLIGATION FILED NOV. 30. 1903.

2 SHEET SSHEET 2.

r I L jj/WW amm UNITED STATES PATENT OFFICE.

, DYNAMO-ELECTRIC MACHINERY.

v No. 811,312.

Specification of Iletters Patent.

Patented Jan. 30, 1906.

Application filed be 30, 1903. Serial No. 183,238.

To all whom, it may concern:

Be it known that I, JOHN HERBERT Sr. HILL MAWDSLEY, a subject of the King of Great Britain, and a resident of Taunton, England, have invented certain new and useful Improvements in Dynamo-Electric Machinery, of which the following is a specification.

My invention relates to improvements in dynamo-electric machinery, and has special reference to pole-pieces and energizing-coils therefor. It embraces polar cores which are split to a considerable depth and the sides spaced some distance apart, so that the separated polar core-pieces have a ventilatingspace between them.

My invention further embraces the following features: pole-cores having particular forms in cross-section or having polar faces of particular shape, or both, the energizing of more than one pole-piece by a single coil, a peculiar disposition of field-magnet, energizing-coils having a certain relation to the armature-coils undergoing commutation, the placing of the sides of such energizing-coils in a position relative to the coil of an armature undergoing commutation, a particular form of polar core-piece, and a particular form of ventilating-space between two such corepieces, the use of an exciting-coil in a particular manner, all as will be hereinafter more particularly referred to in the specification and claims.

In order to show how my invention is to be or may be carried into effect, I shall now refer to the accompanying sheets of drawings, in which Figure I is an end view of part of the magnetic carcass with the energizing-coils shown in section. Fig. II shows a split rhomboidal I pole-face. Fig. III shows a split trapezoidal pieces.

pole-face. Fig. IV shows a split rhomboidal pole-face with a rhomboidal coil. Fig. V shows a similar pole-piece and coil, but in po sition as shown in Fig. I. Fig. VI shows a rhomboidal pole-piece with rectangular coil. Fig. VII shows part of a displayed field of a multipolar machine having split rhomboidal pole-pieces and rectangular coils. Fig. VIII shows part of a displayed field of a multipolar machine as in Fig. VII, but with each alternate pole-piece only provided with an exciting-coil. Fig. IX shows part of a displayed field of a multipolar machine with trapezoidal coils and split trapezoidal pole- Fig. X shows part of a displayed field of a multipolar machine with trapezoidal coils and split trapezoidal pole-pieces, each alternate pole-piece only being provided with an exciting-coil. Fig. XI is a perspective view of a trapezoidal coil bent into shape for actual use.

Referring nowto Fig. I, I there illustrate, partly in end elevation and partly in section, a preferred form of my invention. Here it will be seen that the field consists of a yoke 1 and that each pole consists of two curved horns or core-pieces 2 2, with a more or less wedge-shaped air-space 3 between them, and also that the polar face constituted by the united faces of these two core-pieces is of rhomboidal form. S'uchapole-piece is shown in Fig. II, where it will be seen that the pole-face is of the form of a rhombus and that the split or space between the two 0011- stituent core-pieces lies not parallel to the sides of the pole-piece, but in a direction normal to the ends of the pole-face, or, in other words, parallel to the shaft of the armature, or, what is the same, to the geometric axis of the machine as a whole. The four sides of the quadrilateral figure shown. in Fig. II are equal; but it is obvious that the opposite sides'may be of unequal length, in which case the pole-face is of the form of a rhomboid instead of a rhombus, orthe'oppo site sides instead of being parallel to one-another may be inclined to one another, so that the pole-face thus constituted is of the form shown in Fig. III and which I shall hereinafter refer to as trapezoidal. In all cases the face of the whole pole-piece has the form of a quadrilateral, two sides of which are parallel and the two other sides of which may orni'ay not be parallel, but are always equal and are inclined to the first. 1

5 is a magnetizingcoil. (Shown before bending in Fig. IV and after bending in Fig. V. It is also shown in section and in position in Fig. I.) It will be seen that the coil'is rhomboidal in form, but that the sides 6 6 instead of lying close up to the pole-core are spaced away therefrom and lie in the middle of the interpolar space-that is to say, in the neutral zoneand just over and as close as possible to the coils 4 of the armature which are undergoing commutation, while the ends 7 7 of the coil lie close up to the core-pieces, as is usual.

It will be seen that the separate core-pieces 2 and 2*, which conjointly constitute a polepiece, are curved and that the ventilatingspace a is more or less Wedge-shaped. Al though this is a preferred form, I desire it to be understood that I do not limit myself to such forms in practice, as these corepieces may be straight, if desired, and project at any desired angle and that the ventilatingspace 3 may be varied in shape at will. For example, it may consist of a mere rectangular slot.

Where the coils are rectangular, as in Figs.

VI, VII, and VIII, it will be seen that the sides 6 of the coils are parallel to the armaturecoils, but that when the coils are of rhomboidal or trapezoidal formthat is to say, where the sides of the coils are inclinedthey cut the coils undergoing commutation at a slight angle. In the drawings I have shown the rhomboidal coils in connection with rhomboidal pole-pieces only, rectangular coils in connection with rhomboidal poles only, and trapezoidal coils in connection with trapezoidal pole-pieces only; but I desire it to be understood that I may use rhomboidal coils with trapezoidal pole-pieces, rectangular coils with trapezoidal pole-pieces, and trapezoidal coils with rhomboidal pole-pieces.

I am aware that trapezoidal pole-faces and trapezoidal coils have already been employed in disk machinesthat is to say, in machines where the planes of the pole-faces and of the said coils have been parallel to the plane of rotation of the armature; but in such cases an entirely different effect is obtained, and I desire it to be understood that in my inven tion I limit myself to the widely-different casein which the pole-faces and the planes of the faces of the coils are at right angles to the plane of rotation of the machine.

It is to be noted that in the drawings I have shown the split or ventilating slot as lying parallel to the geometric axis of the machine and not parallel to the sides of the polepieces in which it is cut. I desire it to be understood that while in practice I limit myself to the split being parallel to the geometric axis of the machine at the polar face itself it may at some depth from the actual face be inclined so as no longer to be parallel to the geometric axis of the machine. In other words, the necessity for such parallelism exists only at or near the pole-face, the actual inclination or configuration of the walls of the space away from the pole-face being preferably parallel to the sides of the pole, so that as regular and even a flux may be obtained as is possible.

In speaking of the planes of a pole-piece and of the coils I am of course taking them as being seen when looked at in a direction normal thereto, for it is obvious that the surfaces in question are curved, that being a necessity of construction and of position.

I desire it to be understood that by the term rhomboidal I mean relating not only to the form of a rhomboid, but to the form of a rhombus also, and that by the term trapezoid I mean a quadrilateral figure two of Whose opposite sides are parallel and the other two sides equal and inclined to one another.

Having thus described my invention,what I claim as new, and desire to secure by Letters Patent, is

1. Dynamo-electric machines having magnetizing-coils each surrounding a pole-piece placed with their sides in the neutral zones and close to their armatures and at or about the middle of the interpolar spaces of contiguous poles and spaced away from the polecores.

2. In a dynamo-electric machine a fieldmagnet having each alternate pole-piece only provided with a magnetizing-coil, the said coils each surrounding a pole-piece and placed with its sides in the neutral zones and close to the armature and at or about the middle of the interpolar spaces of contiguous poles and spaced away from the pole-cores.

3. In a dynamo-electric machine, a trapezoidal field-magnet coil, the plane of the face of the coil being at right angles to the plane of rotation of the armature.

4. In a dynamo-electric machine, fieldmagnet coils of uadrilateral form and so placed that two 0 the sides cut the neutral zone at a slight angle and are spaced away from the pole-cores.

5. In a dynamo-electric machine a polepiece having a trapezoidal face and split in a plane parallel and radial to the armatureshaft.

In witness whereof I have hereunto set my hand in presence of two witnesses.

JOHN HERBERT ST. HILL MAWDSLEY.

Witnesses:

JAMES G. LORRAIN. G. F. WARREN. 

